Kitchen sink unit

Modular cabinet construction follows the same, or very similar, steps whatever material is being used. Some jointing methods suit one material more than another; for instance biscuit joints particularly suit MDF, and pocket-hole screws work particularly well with plywood. MFC (melamine-faced chipboard) is probably the most difficult material to joint strongly and so I’ve tried making a few sample joints and testing them to destruction.

Whatever material you use remember that if you want to make standard width units, it’s the outside dimension that’s important. If you use different thicknesses of board material for the sides you will need to compensate for that, by adjusting the width of the internal components.

Finishing MFC UNITS

The big advantage of melamine-faced units is that they don’t need any finishing; once the unit is made it is ready to fit and needs no further treatment. Timber and ply units need several coats of finish, sanded down between each coat, which is obviously very time consuming. I used water-based clear satin varnish because it dries quickly and there’s little smell. Ultimately varnish is not as stain resistant as melamine and does tend to mark if, for instance, wet pans are stored

Tricks of the trade

Make a melamine-faced chipboard cupboard that really lasts For this 600mm wide base unit I bought two 2440mm lengths of 600mm wide melamine-faced furniture board from Wickes. Each board is 15mm thick, lipped on both long sides and of good quality; it costs £9.49 per sheet. Most kitchen units come with a thin, four or six millimetre back panel, but for base units I generally use the same material as the rest of the unit. This has a few advantages; you only need to source and buy one board material, the unit is stronger, and construction is simplified, as there’s no need to cut housings in the sides to fit the back.

I’ve used a Festool saw and guide rail system to cut the boards to length, later in the article I look at different ways of cutting MFC without chipping the boards too much (see Cutting MFC).

1] Cut three 750mm lengths for the sides and back, and a 570mm length for the base panel.

2] The sides and back need cutting down to 570mm wide and the base panel to 500mm; the off-cut is used for the top rail. The base panel is cut to 500mm depth to give some clearance at the back for services.

3] Mark the centre line of the base panel along the lower edge of the side panels. This gives a line to drill and countersink the screw holes.

4] Run a bead of sealant along the bottom face of the sides.

5] Resting the front faces on a flat surface, offer the sides and base panel together. Put a couple of clamps on to hold them in place. One advantage of the Bessey clamps is that they naturally pull the work together reasonably square. Make sure the sides are square to the base then drill pilot holes into the base panel before screwing the sides to the base.

6] Once the base is fixed, stand the cabinet up and mark the centre line of the back panel on the sides. I use a marking guage for this. Drill pilot holes and countersink; this doesn’t need as many screws as the base. Make a mark on the top edge of the sides as a guide to positioning the back.

Using a circular saw to cut MFC Using a saw table to cut MFC Drill screw holes

1] Cut lengths for the sides and back

2] Sides and back are cut down to 750mm wide

3] Drill screw holes along side panels

Applying sealant Assembling the cabinet Marking panels

4] Run a bead of sealant along the side bottom

5] Clamp the sides and base on a flat surface

6] Mark the back panel centre line

7] I’ve placed a length of tissue under the edge of the cabinet to protect the workbench …

8] …before applying sealant to the sides and rear edge of the base panel to keep out any moisture when the unit is fitted.

9] The back is screwed into the base panel and through the sides. Clean off any sealant squeeze out; the advantage of using a white sealant is that it covers any small chips in the edge of the melamine panels. It’s a good idea to stop now and wait for the sealant to ‘tack off’ otherwise wood chips will spoil the finish.

10] If a clamp is fitted across the top it will help hold the top rail in place while the pilot holes are drilled. Apply sealant and screw in place, I used two 50mm chipboard screws each side. Make sure the screws are countersunk. If they are proud they will stop the units fitting tightly.

11] To support the feet, and to give a more secure fixing to the screws, fit a couple of off-cuts of 6mm ply to the base. The ply needs to be fitted 60mm in from the front edge to allow room to fit the plinth.

12] Mark the extent the ply covers the base and apply adhesive, the ply is pressed on and a few screws driven into the bottom edge of the sides to hold.

Protecting your bench from sealant Sealing the cabinet sides Screw the back to the base panel

7] Protect your bench from all the sealant

8] Seal the sides and rear edges against moisture

9] Screw the back to the base panel

Fitting the top rail Marking the base Glueing the ply

10] Fit the top rail with two 50mm screws per side

11] Mark the base for ply strengtheners

12] Use a generous amount of glue for the ply

13] The leg housings are screwed in place through the ply and into the chipboard overlapping the projection over the sides to give them support.

14] Push the legs into the housing.

15] Any raw chipboard edges should be thoroughly sealed by painting or rubbing adhesive/sealant into the edge.

16] The finished cabinet nest to last month’s flat pack.

Using a circular saw to cut MFC Using a saw table to cut MFC Drill screw holes

13] Screw in the leg housings

14] Add the legs

15] Smear sealant over any raw chipboard edges

The finished cabinet

16] The Woodsmith’s unit cost £20 using Wickes board compared to a thinner flat pack unit cost of around £29

Custom unit costs:

After allowing for a shelf I had a 1200mm length of board left over, so the MFC cost for this unit was approximately £14. Legs cost as little as £2 per set from Screwfix and hinges start at about £3 per pair, if we allow a pound for the sealant and fixings, the unit has cost a grand total of £20, compared to £29 for the flat packed unit. The flat pack unit takes about an hour to build, the MFC unit two to three hours; if you have a lot to build you can expect to get that time down.